This invention relates to an automatic accompaniment device for an electronic musical instrument and, more particularly, to improvements in a memory function in automatic performance of chord tones and bass tones.
Known in the art of the automatic accompaniment devices for an electronic musical instrument is a technique of incorporating a memory function for repeating the automatic accompaniment performance even after release of the depressed keys which has determined the chord and the bass. According to this prior art automatic accompaniment device, if a depressed key or keys are released in a mode wherein the memory function is selected (rendered operative), chord tones and bass tones are both played automatically on the basis of the notes of the keys which has been depressed and then released. In a case where, for example, a fingered-chord function is selected as a mode of the automatic accompaniment function and the memory function is also selected (rendered operative), if a plurality of keys which have been depressed in a keyboard allotted for the automatic bass/chord performance (e.g. a lower keyboard) are released, tones of all of the keys which have been depressed before release in the keyboard for the fingered-chord automatic bass/chord performance are automatically played in the form of chord tones in accordance with a predetermined rhythm pattern and, further, bass tones are formed on the basis of the root note and the type of the chord detected in accordance with the keys which have been depressed before release in the fingered-chord automatic bass/chord performance keyboard and such bass tones are automatically played in accordance with the predetermined bass pattern.
In a case where a single-finger function is selected as a mode of the automatic accompaniment function and the memory function is also selected (rendered operative), if a single key which has been depressed in a keyboard allotted for the single-finger automatic bass/chord performance (e.g. the lower keyboard) is released in a state wherein the memory function is selected, chord tones formed on the basis of the note of the single depressed key which is used as the root note and of a chord type designated by suitable means such as depression of a white key or black key in a pedal keyboard are automatically played in accordance with a predetermined rhythm pattern and, further, bass tones formed on the basis of the root note and the chord type are automatically played in accordance with the predetermined bass pattern.
In a case where a custom function is selected as a mode of the automatic accompaniment and the memory function is also selected (rendered operative), if keys which have been depressed in the keyboards allotted for the custom function automatic bass/chord performance (i.e. the lower keyboard and the pedal keyboard) are released, tones of all the keys which have been depressed in the lower keyboard are automatically played as chord tones after release of the keys and, further, bass tones formed on the basis of the note of the single key depressed in the pedal keyboard which is used as the root note and in accordance with the chord type detected on the basis of the tones of the keys which have been depressed in the lower keyboard and with the bass pattern are automatically played. This type of prior art system is illustrated in the U.S. Pat. No. 4,184,401 to Hiyoshi et al.
The prior art automatic accompaniment device is convenient for beginners, as both chord tones and bass tones are automatically played concurrently if the memory function is selected (rendered operative). Such device however is not preferred by middle class or advanced players because a free accompaniment performance is restricted in such device. For example, there arise cases in the musical performance where the player desires to play chord tones manually while he leaves the performance of bass tones to the automatic performance using the memory function or vice versa. The prior art automatic accompaniment device, however, does not allow the player to play chord tones or bass tones alone selectively by the automatic performance using the memory function.